As the sun heats the surface of the oceans, two layers of water result. what separates the layers?

An alloy contains 66 g of pure zinc. what is the percentage of zinc in the alloy? express your answer to two significant figures and include the appropriate units.

If e is the symbol for an element, which two of the following symbols represent isotopes of the same element? 1. e2. e3. ea.1 and 2c.1 and 4b.3 and 4d.2 and 3

Calculate the concentration of all species in a 0.165 m solution of h2co3.